Riwers of Northern New Jersey. 97 
and beheaded (C, D) portions of the captured streams will for a 
time present different stages of approach to establishment. The 
divide on the line of that one of the original streams, C, that is 
nearest to the master stream, A, may reach a final stable position, 
Z; while on the next stream further away from the master, 
the beheaded portion, D, may still retain a short piece above the 
gap in the upper lava sheet, not yet secured by the inverted 
stream, V’; and a third stream, further away still from the mas- 
ter (not shown in figure 7) might remain uncaptured and inde- 
pendent. 
It is by such tests as these that we may hope to recognize the 
occurrence of partial adjustment in the streams of the Watchung 
crescent as a result of their superimposition on the Triassic forma- 
tion from its former Cretaceous cover. The greater the degree 
of complexity in the tests proposed, the more confidence we shall 
have in the theory when the tests successfully meet the facts. 
Hence the reason fcr deductively carrying out the theoretical 
conditions to their extremest consequences in order to increase the 
complexity of the tests that are to be confronted with the facts. 
This, as'a matter of method, seems to me of great practical impor- 
tance in any attempt to decipher the past progress of geographical 
development. 
The admirable contoured topographic maps of New Jersey, 
issued by the Geological Survey of that state under the leadership 
of the late Professor George H. Cook, afforded means of apply- 
ing the deductive tests above outlined without the necessity of 
plodding over all the country concerned ; but however good the 
maps are, it is hardly necessary to say that they can be interpreted 
with a better appreciation of the facts that they represent after an 
excursion on the ground has given the student some personal 
acquaintance with it. This I have tried to gain on various occa- 
sions, maps in hand. 
Atlas sheet number six, including the Central red-sandstone 
area, and the five-mile-to-an-inch geological map of the state pre- 
sent in the clearest manner the facts of form and structure in- 
volved in our problem ; and to my mind, the correspondence be- 
tween theory and fact is very striking. The Pequannock-Passaic 
is the master transverse stream of the region: its preéminence 
was probably due in the beginning to its gathering, from the un- 
submerged Highlands, a greater amount of drainage than be- 
longed to any other stream that ran southeastward down the gen- 
